Ground-state phases of a rotating spin-orbit–coupled Bose-Einstein condensate in an optical lattice

¹ Department of Mathematics and Physics, Shijiazhuang TieDao University - Shijiazhuang 050043, China
² Institute of Applied Physics, Shijiazhuang TieDao University - Shijiazhuang 050043, China
³ Department of Physics, Beijing Normal University - Beijing 100875, China

^(a) wangjiguo@stdu.edu.cn (corresponding author)
^(b) yangshijie@tsinghua.org.cn (corresponding author)

Received: 3 October 2017
Accepted: 20 December 2017

Abstract

We study the ground-state phases of a two-dimensional rotating spin-orbit–coupled Bose-Einstein condensate loaded in a one-dimensional spin-dependent optical lattice. In the absence of rotation, the system undergoes a phase transition from the stripe phase to the supersolid phase gradually for weak spin-orbit coupling strength and directly for strong spin-orbit coupling strength as the depth of the optical lattice increases. With increasing the rotation strength, the stripe phase transforms to the ringlike state, and the domain number of the ringlike state increases when the Bose-Einstein condensate is in the weak depth of the optical lattice. The supersolid phase transforms to the phase with a single domain of a vortex line for small rotation strength, and alternating vortex lines along the x-direction appear for large rotation strength when the Bose-Einstein condensate is in the strong depth of the optical lattice. The spin textures of the ground-state phases are also discussed.